The present invention relates to a method for recycling supercritical waste liquid generated during a process of producing a silica aerogel blanket, and a method for producing a silica aerogel blanket reusing supercritical waste liquid recycled thereby. More particularly, the present invention provides a method for recycling supercritical waste liquid and a method for producing a silica aerogel blanket capable of reducing the production costs and preventing the deterioration in thermal insulation performance of a silica aerogel blanket by adding a metal salt to the supercritical waste liquid by the recycling method.

A sol of inorganic oxide particles is stably dispersed in a hydrophilic organic solvent containing a hydrocarbon such as a paraffinic hydrocarbon or a naphthenic hydrocarbon. The sol contains a dispersion medium containing an organic solvent containing a C.sub.6-18 paraffinic hydrocarbon, a C.sub.6-18 naphthenic hydrocarbon, or a mixture of these, a C.sub.4-8 alcohol having a carbon chain with a carbon-carbon bond in the molecule in an amount of 0.1 to 5% by mass in the entire dispersion medium, and inorganic oxide particles having an average particle diameter of 5 to 200 nm as measured by dynamic light scattering as a dispersoid, wherein the inorganic oxide particles contain a C.sub.1-3 alkyl group bonded to a silicon atom and a C.sub.4-18 alkyl group. The paraffinic hydrocarbon is a normal paraffinic hydrocarbon or an isoparaffinic hydrocarbon. The naphthenic hydrocarbon is a saturated aliphatic cyclic hydrocarbon substitutable with a C.sub.1-10 alkyl group.

A sol of inorganic oxide particles is stably dispersed in a hydrophilic organic solvent containing a hydrocarbon such as a paraffinic hydrocarbon or a naphthenic hydrocarbon. The sol contains a dispersion medium containing an organic solvent containing a C.sub.6-18 paraffinic hydrocarbon, a C.sub.6-18 naphthenic hydrocarbon, or a mixture of these, a C.sub.4-8 alcohol having a carbon chain with a carbon-carbon bond in the molecule in an amount of 0.1 to 5% by mass in the entire dispersion medium, and inorganic oxide particles having an average particle diameter of 5 to 200 nm as measured by dynamic light scattering as a dispersoid, wherein the inorganic oxide particles contain a C.sub.1-3 alkyl group bonded to a silicon atom and a C.sub.4-18 alkyl group. The paraffinic hydrocarbon is a normal paraffinic hydrocarbon or an isoparaffinic hydrocarbon. The naphthenic hydrocarbon is a saturated aliphatic cyclic hydrocarbon substitutable with a C.sub.1-10 alkyl group.

The invention relates to a method of making hybrid organic-inorganic core-shell nano-particles, comprising the steps of a) providing colloidal organic particles comprising a synthetic polyampholyte as a template; b) adding at least one inorganic oxide precursor; and c) forming a shell layer from the precursor on the template to result in core-shell nano-particles. With this method it is possible to make colloidal organic template particles having an average particle size in the range of 10 to 300 nm; which size can be controlled by the comonomer composition of the polyampholyte, and/or by selecting dispersion conditions. The invention also relates to organic-inorganic or hollow-inorganic core-shell nano-particles obtained with this method, to compositions comprising such nano-particles, to different uses of said nano-particles and compositions, and to products comprising or made from said nano-particles and compositions, including anti-reflective coatings and composite materials.

The invention relates to a method of making hybrid organic-inorganic core-shell nano-particles, comprising the steps of a) providing colloidal organic particles comprising a synthetic polyampholyte as a template; b) adding at least one inorganic oxide precursor; and c) forming a shell layer from the precursor on the template to result in core-shell nano-particles. With this method it is possible to make colloidal organic template particles having an average particle size in the range of 10 to 300 nm; which size can be controlled by the comonomer composition of the polyampholyte, and/or by selecting dispersion conditions. The invention also relates to organic-inorganic or hollow-inorganic core-shell nano-particles obtained with this method, to compositions comprising such nano-particles, to different uses of said nano-particles and compositions, and to products comprising or made from said nano-particles and compositions, including anti-reflective coatings and composite materials.

The production method of the present invention can reuse a non-impregnated catalyzed sol, which has been typically discarded, by recovering the catalyzed sol, which is not impregnated in impregnating of a catalyzed sol into a blanket base, to stop gelating the catalyzed sol, and then using this in subsequently preparing a catalyzed sol.

Provided is a method for drying a wet-gel blanket which can have an excellent heat insulation performance by minimizing shrinkage of a gel network structure that occurs during drying, and has excellent drying efficiency versus time, and a method for producing an aerogel blanket using same.

Provided is a method for drying a wet-gel blanket which can have an excellent heat insulation performance by minimizing shrinkage of a gel network structure that occurs during drying, and has excellent drying efficiency versus time, and a method for producing an aerogel blanket using same.

The present invention relates to an aerogel blanket including an aerogel structure and a substrate for a blanket, wherein the aerogel structure includes a three-dimensional network structure formed by a plurality of aerogel particles aggregated or bonded, and an average aerogel structure size (D.sub.50) measured by spraying 10 ml of dry powder of the aerogel structure with air at a pressure of 15 psi, and using laser diffraction of 780 nm wavelength is 5 μm to 10 μm.

A colloidal silica is disclosed that contains, with high purity, silica particles having an appropriate particle density, a high aggregation ratio, and a high alkoxy group content, and to provide a method for producing the colloidal silica in a simple manner at reduced costs. The colloidal silica containing silica particles is disclosed, wherein the silica particles have an average primary particle size of 33 nm or more, an aggregation ratio of 1.2 or more, and a particle density of 1.95 or more, the silica particles contain 1000 ppm by mass or more of alkoxy groups per gram of the silica particles, the proportion of the number of silica particles having an equivalent circle diameter under 20 nm is less than 15%, and the silica particles contain a primary amine in an amount of 5 μmol or more per gram of the silica particles.